<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>label标签</title>
</head>
<body>
    <label for="username">用户名：</label> <input type="text" id="username" name="username"> <br>
    <label for="sexnan">男</label> <input type="radio" name="sex" id="sexnan">
    <label for="sexnv">女</label> <input type="radio" name="sex" id="sexnv" checked="checked">
    
</body>
</html>